Electrolyte solution for rechargeable lithium battery and rechargeable lithium battery including the same

Abstract

Examples of the disclosure include an electrolyte solution for a rechargeable lithium battery, and a rechargeable lithium battery including the electrolyte solution. The electrolyte solution includes a non-aqueous organic solvent, a lithium salt, a first additive, and a second additive capable of ring-opening the first additive, and the content ratio of the second additive to the first additive is about 1 to about 3.

What is claimed is: 
     
         1 . An electrolyte solution for a rechargeable lithium battery, the electrolyte solution comprising:
 a non-aqueous organic solvent;   a lithium salt;   a first additive represented by Formula 1 below; and   a second additive capable of ring-opening the first additive,   wherein the content ratio of the second additive to the first additive is about 1 to about 3,   
       
         
           
           
               
               
           
         
         wherein in Formula 1 above, R 1  to R 6  each independently comprise one of a hydrogen atom and a substituted or unsubstituted C1 to C10 alkyl group. 
       
     
     
         2 . The electrolyte solution for a rechargeable lithium battery of  claim 1 , wherein the first additive is represented by Formulas 1-1 to 1-4 below: 
       
         
           
           
               
               
           
         
       
     
     
         3 . The electrolyte solution for a rechargeable lithium battery of  claim 1 , wherein the first additive has a concentration of about 0.01 wt % to about 5 wt % of a total weight of the electrolyte solution. 
     
     
         4 . The electrolyte solution for a rechargeable lithium battery of  claim 1 , wherein the second additive comprises at least one of LiBF 4 , LiDFOB, NaBF 4 , KBF 4 , RbBF 4 , and CsBF 4 . 
     
     
         5 . The electrolyte solution for a rechargeable lithium battery of  claim 1 , wherein the second additive has a concentration of about 0.01 wt % to about 5 wt % of a total weight of the electrolyte solution. 
     
     
         6 . The electrolyte solution for a rechargeable lithium battery of  claim 1 , wherein the non-aqueous organic solvent comprises a carbonate-based solvent, and
 the carbonate-based solvent comprises at least one of ethylene carbonate (EC), propylene carbonate (PC), propyl propionate (PP), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methylethyl carbonate (MEC), and butylene carbonate (BC).   
     
     
         7 . The electrolyte solution for a rechargeable lithium battery of  claim 1 , wherein the non-aqueous organic solvent comprises ethylene carbonate (EC), propylene carbonate (PC), and propyl propionate (PP), and
 wherein the ethylene carbonate (EC), the propylene carbonate (PC), and the propyl propionate (PP) are present at a volume ratio of 1:a:b, where:   “a” is in a range of 1 to 3, and   “b” is in a range of 5 to 8.   
     
     
         8 . The electrolyte solution for a rechargeable lithium battery of  claim 1 , wherein the lithium salt comprises at least one of LiPF 6 , LiSbF 6 , LiAsF 6 , LiClO 4 , LiAlO 2 , LiAlCl 4 , LiPO 2 F 2 , LiCl, LiI, LiN(SO 3 C 2 F 5 ) 2 , Li(FSO 2 ) 2 N, (lithium bis (fluorosulfonyl) imide (LiFSI)), and LiC 4 F 9 SO 3 . 
     
     
         9 . The electrolyte solution for a rechargeable lithium battery of  claim 1 , wherein the lithium salt has a concentration of about 0.1 M to about 2.0 M. 
     
     
         10 . A rechargeable lithium battery comprising:
 a positive electrode including a positive electrode active material;   a negative electrode including a negative electrode active material; and   the electrolyte solution of  claim 1 .   
     
     
         11 . The rechargeable lithium battery of  claim 10 , wherein the positive electrode active material comprises a lithium composite oxide represented by Formula 2 below: 
       
         
           
             
               
                 
                   
                     
                       Li 
                       x 
                     
                     ⁢ 
                     
                       M 
                       y 
                       1 
                     
                     ⁢ 
                     
                       M 
                       z 
                       2 
                     
                     ⁢ 
                     
                       M 
                       
                         1 
                         - 
                         y 
                         - 
                         z 
                       
                       3 
                     
                     ⁢ 
                     
                       O 
                       
                         2 
                         - 
                         a 
                       
                     
                     ⁢ 
                     
                       X 
                       a 
                     
                   
                 
                 
                   
                     Formula 
                     ⁢ 
                         
                     2 
                   
                 
               
             
           
         
         wherein: 
         0.5≤x≤1.8, 0≤a≤0.05, 0<y≤1, 0≤z≤1, and 0≤y+z≤1 are satisfied, 
         M 1 , M 2 , and M 3  each independently include at least one of nickel (Ni), cobalt (Co), manganese (Mn), aluminum (Al), boron (B), barium (Ba), calcium (Ca), cerium (Ce), chromium (Cr), iron (Fe), molybdenum (Mo), niobium (Nb), silicon (Si), strontium (Sr), magnesium (Mg), titanium (Ti), vanadium (V), tungsten (W), zirconium (Zr), or lanthanum (La), and a combination thereof, and 
         X includes at least one of fluorine (F), sulfur(S), phosphorus (P), or chlorine (CI). 
       
     
     
         12 . The rechargeable lithium battery of  claim 10 , wherein the positive electrode active material comprises lithium iron phosphate (LiFePO 4 ). 
     
     
         13 . The rechargeable lithium battery of  claim 10 , wherein the negative electrode active material comprises at least one of a carbon-based negative electrode active material, a Si-based negative electrode active material, and a Sn-based negative electrode active material. 
     
     
         14 . The rechargeable lithium battery of  claim 10 . wherein the rechargeable lithium battery is one of a cylindrical battery, a prismatic battery, a pouch-type battery, and a coin-type battery.